Green Coffee Extract Research

Supplementation with an extract made from unroasted coffee beans – Green Coffee Bean Extract as it's called – can help overweight people who are on a diet to lose extra weight. Researchers at the University of Scranton write about this in a human study, published in Diabetes, Metabolic Syndrome and Obesity. Sounds good, but we don't entirely trust the research.

Coffee beans are bursting with chlorogenic acid analogues. Chlorogenic acid is created by adding caffeic acid to quinic acid.

Green coffee beans contain a number of chlorogenic acid analogues. When coffee is roasted lots of these analogues are lost. Nevertheless big coffee drinkers can ingest up to a gram or more of chlorogenic acid analogues daily.

Extracts containing chlorogenic acid analogues have been on the market for years. They are found in diet products. One of these extracts is GCA, made by Applied Food Sciences. It consists of 46 percent chlorogenic acid analogues and 2-4 percent caffeine.

Although there's no mention in the publication, the study that has appeared in Diabetes, Metabolic Syndrome and Obesity was funded by Applied Food Sciences. The research was carried out in India.

Sixteen fairly overweight people aged between 22 and 46 participated in the 22-week-long study. This consisted of three six-week phases, in which the subjects were given a placebo [PL], 700 mg Green Coffee Bean Extract [LD], or 1050 mg Green Coffee Bean Extract [HD] daily. During each phase there was a wash-out period of two weeks during which the subjects took nothing [WO].

The figure below shows that during the phases when the subjects took a placebo little or nothing happened. During the phases that the subjects took Green Coffee Bean Extract they lost weight.

After one six-week placebo treatment, one six-week period of taking 700 mg Green Coffee Bean Extract, one six-week period of taking 1050 mg Green Coffee Bean Extract and two two-week wash-out periods the subjects lost 8.1 kg in bodyweight.

An eight-kilogram weight loss – about 5.3 kg fat and 2.8 kg lean body mass – in 22 weeks is a pretty impressive result. A bit too good, for a supplement. But after bit of googling we discovered that the results were not due to supplementation alone.

During the study the subjects ate 2400 kcal per day. It's not mentioned in the study but the subjects also burned more than 400 kcal per day through exercise. Dietician Diane Kress reports this in her blog, quoting the lead author of the study, Joe Vinson. [thewhistleblog.blogspot.com/2012/07]

"Please note that 2400 calories/day with a 400 calorie exercise burn is not a typical intake for an obese adult", Kress writes. "A 2400 calorie dietary intake with 400 calories of exercise burn is typically a weight loss diet for an obese adult."